Synthesis, characterization and osteoconductivity properties of bone fillers based on alendronate-loaded poly(ε-caprolactone)/hydroxyapatite microspheres

A superior drug controlled release system capable of achieving efficient osteogenesis is in imperative demand because of limited bone substitute tissue for the treatment of bone defect. In the present study, we investigated the potential of using poly(ε-caprolactone)–hydroxyapatite (PCL–HA) composite microspheres as an injectable bone repair vehicle by controlled release of alendronate (AL), a medicine that belongs to the bisphosphonates family. The PCL/HA–AL microspheres were prepared with solid/oil/water emulsion technique, which included two processes: (1) AL was loaded on the hydroxyapatite nanoparticles; (2) the HA–AL complex was built in the PCL matrix. The spherical PCL/HA–AL microspheres were characterized with its significantly improved encapsulation efficiency of hydrophilic AL and better sustained release. Human bone mesenchymal stem cells (hMSCs) were cultured on the surface of these microspheres and exhibited high proliferative profile. Specifically, in osteogenic medium, hMSCs on the surface of PCL/HA–AL microspheres displayed superior osteogenic differentiation which was verified by alkaline phosphatase activity assay. In conclusion, by presenting strong osteogenic commitment of hMSCs in vitro, the PCL/HA–AL microspheres have the potential to be used as an injectable vehicle for local therapy of bone defect.     

深圳市天然气安全应急储备及事故气源的研究

分析了深圳市建设天然气安全应急储备及事故气源的必要性,通过对深圳市天然气产业链中各环节之间相互关系的分析,提出了建设实施方案。     

综合型贯标工作在水利水电企业中的实施

随着水利水电建设工程不断向坝体高、规模大、结构复杂及工期要求紧、质量安全要求高的方向发展,施工的复杂性、难度性和风险性不断增加。工程建设与工程所在地居民安全、生活环境之问的关系愈加密切,各种人文、社会和环境方面的矛盾和问题时常出现。党和政府提出的构建和谐社会的战略纲领,为工程项目建设和谐工地指明了方向。     

经向夹衬加强筋机织物及双引纬织造的研究

提出经向夹衬加强筋机织物的结构,介绍其形成原理及方法,并通过实验及讨论,提出双梭口织机引纬、打纬、送经和卷取机构的改造方案。该结构改善了纤维或纱线在织物及其复合材料中的空间分布形态,从而也能加强其物理机械性能,扩大应用领域。     

Simulation annealing diagnosis algorithm method for optimized forecast of the dynamic response of floating offshore wind turbines

Design of floating offshore wind turbines(FOWTs)needs reliable and innovative technologies to overcome the challenges on how to better predict the dynamic respo...     

The globally asymptotic stability analysis for a class of recurrent neural networks with delays

This paper considers the problem of global stability of neural networks with delays. By combining Lie algebra and the Lyapunov function with the integral inequality technique, we analyze the globally asymptotic stability of a class of recurrent neural networks with delays and give an estimate of the exponential stability. A few new sufficient conditions and criteria are proposed to ensure globally asymptotic stability of the equilibrium point of the neural networks. A few simulation examples are presented to demonstrate the effectiveness of the results and to improve feasibility.     

JSP技术在Web数据库中的应用研究

JSP技术的应用越来越广泛,特别是在Web数据库开发中体现出强大的优势,该文介绍了JSP实现Web数据库开发的两种模式,以及以JDBC为基础的Web数据库的实现。     

A new methodology for identification of critical lines using damping sensitivity analysis

When an inter-area mode dominates a low-frequency oscillation in a stressed condition, control of the active power flow of interface lines, with compensating devices, can effectively reduce the electromechanical power oscillations. In general, interface lines in which inter-area oscillations are large are considered to be good locations for installation of compensating devices. A sensitivity analysis with respect to change in active power flow can provide an important factor in electric power system operation. This paper proposes a new methodology to calculate the damping sensitivity with respect to change in active power flow, which can be useful for accurate selection of critical lines from the viewpoint of small-signal stability. In the proposed methodology, a damping sensitivity index is used to select the critical lines to damp power system oscillations. This paper describes how to derive the damping sensitivity for the selected mode and illustrates an example applying the proposed algorithm to a simple two-area system and the New England 39-bus test system.     

Correction strategy of fuel injection quantity during pilot-main injection for common rail system

Journal of Mechanical Science and Technology - Common rail system is a key technology of energy saving and emission reduction for modern diesel engines. Multiple injection, as one of the most...